Improvement in railway signals



(120.) l I 2 Sheets--SheetL C'. D. TISDALE.

Imprvement ixn Railway Signals.

No. 122,202, Patented De. 26,1871.

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c.-.D. TISDALL improvement in Railway Signals.` N0 122,202

FatentedDec. 26

UNITED STATES ATENT CHARLES D. TISDALE, OF BOSTON, MASSACHUSETTASSIGNORTO HIMSELF AND SAMUEL SHACKELL, OF SAME PLACE.

IMPROVEMENT IN RAILWAY SIGNALS.

Specification forming part of Letters Patent No. 122,202, dated December26, 1871.

To all whom it may concern:

`Be it known that I, CHARLES D. TIsDALE, of Boston, in the county ofSuffolk and State of Massachusetts, have invented an Improvement inOperating Signals, &c.; and I do hereby declare that the following,taken in connection with the drawing which accompanies and forms part ofthis specification, is a description of my invention sulicient to enablethose skilled in the art to practice it.

My invention relates to an improved method of operating railway signalsfrom points more or less remote. The invention consists, primarily, incombining with the signal to be raised or lowered a piston working in acylinder and supported upon liquid contained therein, the cylinder beingconnected by a tube extendin g to the point at which the raising orlowering of the signal is to be effected, at which point the tube or acylinder connected therewith contains another piston resting upon theliquid, with which the whole length of tube is charged, so that, bydownward pressure upon the pistou at the operating point, thepiston-supported signal or other object, however distant, will besimultaneously raised and made conspicuously visible, while, by raisingsaid piston, the signal or other object will be correspondingly lowered.y By my invention signals upon` railroads are arranged at certaindistances apart, and to be operated by the train or engine so that asignal shall be raised by a passing engine, and then lowered by the sameengine as it passes the next signal and by the act of raising saidsecond signal, and so on, the respective signals being at a distanceapart equal to such distance apart as trains may safely run 5' orsimilar signals in each direction may be operated from a station, sothat at any delay to a train at a station, signals may be raised at asuitable distance therefrom in either direction, to give timely noticefor the arrest of approaching trains. The drawing represents a hydraulicor liquidcontaining tubeand signal mechanism, combined or connected witha railway.

A represents the point at the station at which there may be located asignal; B and G, points at 'suitable distances from such station in eachdirection at which to locate safety-signals. a denotes the tubeextendingalongside the track and buried at a suitable depth. At the station-pointA a vertical tube, b, extends up from said tube a, and at the points Band C are similar vertical tubes c d. The horizontal tube is chargedwith a suitable liquid, and in each of the vertical tubes is located apiston, c, f, or g, supported by and upon the liquid, a rod, It,extending up from each piston and having upon its top a signal-ball,lantern, or other signalizing-object, fi, lo, or l. By

, depressing or by raising either one of these signals, one or both of'the others will be raised or lowered. Suppose a train to be passing thepoint B. By a suitable projection from the enginedahe signal i will beraised; as, for instance, an incline or lifterrattached tothe engine maypass under a projection, m, and raise the signalrod. The weight of thepistonin the cylinder d will then cause it to descend, (as the liquid inthe cylinder lowers,) and as the engine passes the signalC, which islocated at a distance from B equal to the distance apart at which trainscan safely run the signal at B will be raised and the signal at Alowered. The reverse of these opera-tions may bring the signals into4position; as, for instance, the signal may be a red ball or other easilydistinguishable object, surrounded by a stationary tube, u, having anopening or openings, c, and depression of the rod by the passing enginemay be made tobriug theball opposite to the opening or into position t-obe seen by an approaching train, depression of the next signal-rodbringing its signal into position, and bringing the former one intoconcealed position. One signal may be used without the other, the signalbeing' brought into position by the passing engine, as described, andthrown from position' by the mechanism operated by the engine to raiseor lower a piston-rod at the proper distance from the signal vat whichit is to be concealed. In either case the liquid-charged tube and thepistons for communicating the motion through the agency of the liquidand the pressure of the pistons thereon, is to be the means of operatingthe signal. To operate either or both ot' the signals from the point A,the vertical tube b is provided with a piston, e, and the horizontaltube may have one or Vmore cocks, p g. By opening cock p and closingcock q, and depressing or raising 'the rod h, the signal at B may beraised or lowered. In the same' manner, by closing cockb and openingcock q, the signal at U may be raised or lowered. By having suitablestops for'arresting the movement of each signal-rod at a certain height,both signals may be raised or lowered by lowering or raising the rod h.Two long arms or inclines may be jointed to the pin projecting from thesignal-rod, as seen at Fig. 3, the point of one incline being slightlyhigher than the other. An engine coming in one'direction has upon itsside adjacent to the signal, a projection which runs under the point ofthe arln it is approaching and raises both the arms and the signal,While the engine coming in an opposite direction has upon its sideadjacent to the signal, a projection Which runs over the point ofthe armit approaches and presses down the arrs` and the signal. e l

Thus, trains ruiming over the same track from trunkand branch tracks mayknow of the passage of prior trains, the signal shown at C bein gconnected with cooperating signals, as beforedescribed.

. rI he station-signal A may be operated by direct application of thehand to the rod h, or from the inside of the station-house, or from someother point, and may be used simply to display a station-signal, or tooperate by means ofthe distant signals, to notify approaching trains ofpreoccupation of the track at the station, or `that the othersi Iclaim- 1. In connection With a railway track, a horizontalliquid-charged tube having vertical piston cylinders, upon the rods ofwhich are placed signals, said rods having. projections which are movedby a passing engine or car, the movement of one rod and its signaletectingthe movement of the next. piston and its signal, substantiallyas described. y

2. In combination with two or more signals mounted upon the pistons ofthe hydraulic tubes the cock p q, so arranged that either signal may beoperated from the station Without effecting gna] or signals,substantially as described.

3. The jointed inclines or arms having their outer ends at differentelevations, (as shown in Fig. 3,) so that an engine in passing `in onedirection raises the signal, and lin passing in the other directionlowers the signal, substantially as described. y

Executedthe 22dday of September, A. D. 1871. U. D. TISDALE.

Witnesses FRANCIS GOULD,

they may or may not approach.

M. W. FROTHINGHAM.

